Felling head reciprocating blade type

ABSTRACT

A tree feller skidder comprising a mobile, self-propelled unitary vehicle, including a tracked undercarriage having a platform on which is mounted an operator&#39;&#39;s station for effecting operation of the vehicle and various components mounted thereon. The components mounted thereon include an extendible and retractable variable-reach boom mounted for slewing about a vertical axis and having a felling head pivotally attached to the free end thereof, pivotal movement being about a horizontal axis and controlled by a hydraulic motor. The felling head consists of a grapple and shear mounted in fixed spaced relation relative to one another and each has jaw members movable in a direction toward and away a plane passing between the jaw members. The grapple grasps a vertical standing tree and the shear located therebelow severs the tree from its stump, the grapple and shear jaws being controlled by respective ones of two different hydraulic actuators. The shear includes a pair of shear blades mounted on a frame, each by a link member and one further pivotal connection, the latter, in one form, consisting of a cam and cam follower respectively, a slot in the frame and a pin on the respective shear blade or holder therefor. A further component mounted on the vehicle consists of a bunk for anchoring the end of the felled trees to the vehicle and includes an upwardly facing jaw controlled from the operator&#39;&#39;s station, the jaw being defined by a plurality of arcuate arms pivotally mounted and spaced longitudinally along the length of the bunk between a pair of upstanding posts.



1. A felling head comprising in combination: a. a grapple having: i. a frame, ii. a pair of jaw members at least one of which is pivotally mounted on said frame for movement toward and away from the other and together providing a grapple jaw which may be selectively opened and closed relative to a selected plane passing between said jaw members, and iii. first power means connected to said movable grapple jaw member selectively to open and close said grapple jaw; b. a shear rigidly secured to said frame in fixed spaced relation, relative to said grapple jaw along said plane, said shear including i. a pair of cutting members mounted on said frame for movement relative thereto, each of said cutting members comprising a shear blade having a cutting edge movable in a direction toward and away from said selected plane respectively severing an article grasped by the grapple and receiving an elongated article to be severed, and ii. second power means controllably moving said cutting members relative to one another and said frame in a direction toward and away from said selected plane; and c. pivot means on said frame, adjacent said grapple and shear jaws, for pivotally mounting said felling head directly on an extendible and retractable boom or the like.
 2. A felling head as defined in claim 1 wherein each of said grapple jaw members is pivotally mounted on said frame and movable about respective ones of a pair of axes substantially parallel to one another and said selected plane.
 3. A felling head as defined in claim 1 wherein the pivot axes in each pair of jaw members are offset with respect to one another respectively on opposite sides of said plane.
 4. A felling head as defined in claim 1 including link and pivot means interconnecting said shear blades and frame pivotally and reciprocally mounting the shear blades on said frame.
 5. A felling head as defined in claim 3 including link and pivot means interconnecting said shear blades and frame pivotally and reciprocally mounting the shear blades on said frame.
 6. A felling head comprising in combination; a. a grapple having: i. a frame, ii. a pair of jaw members at least one of which is pivotally mounted on said frame for movement toward and away from the other and together providing a grapple jaw which may be selectively opened and closed relative to a selected plane passing between said jaw members, and iii. first power means connected to said movable grapple jaw member selectively to open and close said grapple jaw; b. a shear rigidly secured to said frame in fixed spaced relation, relative to said grapple jaw along said plane, said shear including: i. a pair of cutting members each mounted on said frame for movement relative thereto by a pair of pivots, one of which is slidable relative to the frame whereby eAch cutting member moves along a linear path and simultaneously pivots about an axis angularly disposed with respect to said path, each of said cutting members comprising a shear blade having a cutting edge movable in a direction toward and away from said selected plane respectively severing an article grasped by the grapple and receiving an elongated article to be severed; and ii. second power means controllably moving said cutting members relative to one another and said frame in a direction toward and away from said selected plane; and c. pivot means on said frame, adjacent said grapple and shear jaws, for pivotally mounting said felling head directly on an extendible and retractable boom or the like.
 7. A felling head comprising in combination: a. a grapple having: i. a frame, ii. a pair of jaw members at least one of which is pivotally mounted on said frame for movement toward and away from the other and together providing a grapple jaw which may be selectively opened and closed relative to a selected plane passing between said jaw members, and iii. first power means connected to said movable grapple jaw member selectively to open and close said grapple jaw; b. a shear rigidly secured to said frame in fixed spaced relation, relative to said grapple jaw along said plane, said shear including; i. a pair of cutting members each mounted on said frame for movement relative thereto by a lever pivotally connected at spaced positions respectively to the cutting member associated therewith and the frame and one further pivotal connection between the cutting member and the frame, said levers being located one on each of opposite sides of said plane with their pivot axes disposed substantially parallel thereto and said further pivotal connection between the respective cutting members and the frame being located between the pivotal connections of the levers to said frame, each of said cutting members comprising a shear blade having a cutting edge movable in a direction toward and away from said selected plane respectively severing an article grasped by the grapple and receiving an elongated article to be severed, and ii. second power means controllably moving said cutting members relative to one another and said frame in a direction toward and away from said selected plane; and c. pivot means on said frame, adjacent said grapple and shear jaws, for pivotally mounting said felling head directly on an extendible and retractable boom or the like.
 8. A felling head as defined in claim 7 wherein said further pivotal connections are located one on each of opposite sides of said selected plane.
 9. A felling head as defined in claim 7 wherein said second power means comprises a hydraulic piston-cylinder assembly interconnecting said pair of levers.
 10. A felling head comprising in combination: a. a grapple having: i. a frame, ii. a pair of jaw members at least one of which is pivotally mounted on said frame for movement toward and away from the other and together providing a grapple jaw which may be selectively opened and closed relative to a selected plane passing between said jaw members, and iii. first power means connected to said movable grapple jaw member selectively to open and close said grapple jaw; b. a shear rigidly secured to said frame in fixed spaced relation, relative to said grapple jaw along said plane, said shear including; i. a pair of cutting members each mounted on said frame for movement relative thereto by a lever pivotally connected at a pair of spaced positions respectively to the shear frame and shear blade associated therewith and a further pivotal connection, said levers being located one on each of opposite sides of said selected plane and having the pivotal connection of the levers to said frame located respectively adjacent opposed ends of the frame and said further pivotal connections being located therebetween, each of said cutting members comprising a Shear blade having a cutting edge movable in a direction toward and away from said selected plane respectively severing an article grasped by the grapple and receiving an elongated article to be severed, and ii. second power means controllably moving said cutting members relative to one another and said frame in a direction toward and away from said selected plane; and c. pivot means on said frame, adjacent said grapple and shear jaws, for pivotally mounting said felling head directly on an extendible and retractable boom or the like.
 11. A felling head as defined in claim 7 wherein each lever includes a portion projecting from said shear frame in a direction opposite to that of the shear blades.
 12. A felling head as defined in claim 11 wherein said second power means comprises a hydraulic piston-cylinder assembly interconnecting said projecting portion of said levers thereby locating the shear blades and hydraulic cylinder respectively on opposite sides of the frame.
 13. A felling head as defined in claim 7 wherein the cutting edges of said shear blades are movable in a common plane.
 14. A felling head as defined in claim 11 wherein each said shear blade is a substantially flat platelike member having a cutting edge and wherein the cutting edge of said flat plate members is movable toward and away from one another in a common plane.
 15. A felling head as defined in claim 7 wherein said shear blades each having a longitudinally extending cutting edge and wherein said cutting edges are located substantially in abutting face-to-face relation in a shear jaw-closed position.
 16. A felling head as defined in claim 7 wherein said further pivot is a sliding pivot confined to a path angularly disposed with respect to the direction of reciprocal movement of the shear blades.
 17. A felling head comprising in combination; a. a grapple having: i. a frame, ii. a pair of jaw members at least one of which is pivotally mounted on said frame for movement toward and away from the other and together providing a grapple jaw which may be selectively opened and closed relative to a selected plane passing between said jaw members, and iii. first power means connected to said movable grapple jaw member selectively to open and close said grapple jaw; b. a shear rigidly secured to said frame in fixed spaced relation, relative to said grapple jaw along said plane, said shear including: i. a pair of cutting members each mounted on said frame for movement relative thereto by a lever pivotally connected to the shear blade associated therewith and the frame at respective first and second positions and a further pivot connection together causing each cutting member to move along a linear path and simultaneously pivot about an axis angularly disposed with respect to said path during movement of such cutting members in a direction toward and away from one another, each said further pivot connection comprising a sliding pivot confined to a path angularly disposed with respect to the direction of reciprocal movement of the shear blades and including an elongated slot in the frame and a portion of the cutting member projecting into said slot for sliding therealong, each of said cutting members comprising a shear blade having a cutting edge movable in a direction toward and away from said selected plane respectively severing an article grasped by the grapple and receiving an elongated article to be severed, and ii. second power means controllably moving said cutting members relative to one another and said frame in a direction toward and away from said selected plane; and c. pivot means on said frame, adjacent said grapple and shear jaws, for pivotally mounting said felling head directly on an extendible and retractable boom or the like.
 18. A felling head as defined in claim 17 wherein said path and pivotal connection of the lever to the frame and cutting member are so related as to effect arcuate movement of the cutting edGe of each respective cutting member during movement thereof.
 19. A felling head as defined in claim 7 including a guide channel in the frame and wherein each of said shear blades has a portion thereof slidably mounted in said guide channel.
 20. A felling head as defined in claim 7 including a separate shear and grapple frame, said shear comprising a pair of flat, substantially parallel plates disposed in selected spaced relationship and providing a guide channel for said shear blades, each of said shear blades having a portion disposed between said plates and means securing said shear frame to said grapple frame.
 21. A felling head as defined in claim 1 characterized in that said grapple jaw extends longitudinally along said plane from a position in close proximity to said shear to a position remote therefrom and thereby permits grasping a longitudinal length of tree to facilitate handling the same.
 22. A felling head as defined in claim 1 wherein the pivot means on said frame for pivotally connecting said felling head directly to an extendible and retractable boom has the pivot axis thereof substantially perpendicular to said selected plane.
 23. A felling head as defined in claim 22 characterized in that the pivot axis of the mounting of the felling head and the pivot axes of the grapple jaw members are substantially perpendicular to one another.
 24. A felling head comprising in combination: a. a grapple having: i. a frame, ii. a pair of jaw members at least one of which is pivotally mounted on said frame for movement toward and away from the other and together providing a grapple jaw which may be selectively opened and closed relative to a selected plane passing between said jaw members, and iii. first power means connected to said moveable grapple jaw member selectively to open and close said grapple jaw; b. a shear rigidly secured to said frame in fixed spaced relation, relative to said grapple jaw along said plane, said shear including: i. a channel in a selected portion of said frame, a pair of cutting members mounted on said frame for movement relative thereto, each of said cutting members comprising a shear blade having a cutting edge movable in a direction toward and away from said selected plane respectively severing an article grasped by the grapple and receiving an elongated article to be severed, a portion of each of said cutting members being slidable in said channel with the cutting edge of one cutting member facing the cutting edge of the other, said cutting members being connected to said shear frame by respective ones of a pair of levers, one lever being pivotally connected to the frame adjacent one end of said channel and the other lever pivotally connected to the frame adjacent the opposite end of said channel, means pivotally connecting said levers to respective ones of the shear blades, said shear blades further being connected to the shear frame by a sliding pivot comprising a cam and a cam follower respectively associated with one or the other of said frame and cutting members, and ii. second power means controllably moving said cutting members relative to one another and said frame in a direction toward and away from said selected plane; and c. pivot means on said frame, adjacent said grapple and shear jaws, for pivotally mounting said felling head directly on an extendible and retractable boom or the like.
 25. A felling head comprising in combination a grapple and a shear rigidly secured to a common frame in fixed spaced relation relative to one another, said grapple including a jaw defined by a pair of members pivotally mounted on said frame for movement about respective ones of a pair of axes disposed in spaced relation with respect to one another, said members being movable by pivoting about their respective pivots in a direction toward and away from a plane located therebetween and substantially parallel to such pivot axes and said shear also including a jaw similarly oriented With respect to said frame, said shear jaw being defined by a frame and a pair of shear blades pivotally connected to said frame at respective positions located on opposite sides of said plane and each having a cutting edge movable in a direction toward and away from the other and which direction is also toward and away from said plane respectively to sever and receive an elongated article, first power means connected to said grapple jaw members selectively opening and closing said grapple jaw and second power means selectively opening and closing said shear jaw.
 26. A felling head comprising in combination: a. a grapple having a frame, a pair of members each pivotally mounted on said frame, and together providing a grapple jaw which may be selectively opened and closed relative to a selected plane passing between said members, and first power means interconnecting said pair of members to pivot the same about their respective pivotal connections to the frame selectively opening and closing said grapple jaw; and b. a shear rigidly secured to said frame in fixed spaced relation, relative to said grapple, along said plane, said shear including a frame, a pair of cutting members, means mounting said cutting members on said shear frame comprising a pair of lever arms each pivotally connected to said frame and a selected portion of respective ones of said pair of cutting members, the pivotal connection of said lever arms to said frame being disposed in selected spaced relationship with respect to one another on opposite sides of said plane, and a further pivotal connection between respective ones of said pair of cutting members and said frame, each of said cutting members comprising a shear blade having a substantially straight cutting edge which, in a shear jaw-closed position, are substantially parallel to one another in face-to-face abutting relation and, in a shear jaw-open position, converge inwardly toward one another in a direction toward the frame and thereby provide a widemouthed jaw in the latter position for receiving an article to be severed, said cutting members being movable in a direction toward and away from said selected plane for respectively severing an article grasped by the grapple and receiving an elongated article to be severed, and second power means for moving said cutting members relative to said selected plane.
 27. A felling head as defined in claim 26 wherein said grapple jaw extends longitudinally along said plane from a position in close proximity to said shear to a position remote thereof and thereby permits grasping a longitudinal length of tree to facilitate handling the same.
 28. A felling head comprising in combination: a. a grapple having a frame, a pair of members each pivotally mounted on said frame, and together providing a grapple jaw which may be selectively opened and closed relative to a selected plane passing between said members, and first power means interconnecting said pair of members to pivot the same about their respective pivotal connections to the frame selectively opening and closing said grapple jaw; and b. a shear rigidly secured to said frame in fixed spaced relation, relative to said grapple, along said plane, said shear including a frame, a pair of cutting members, means mounting said cutting members on said shear frame comprising a pair of lever arms each pivotally connected to said frame and a selected portion of respective ones of said pair of cutting members, the pivotal connection of said lever arms to said frame being disposed in selected spaced relationship with respect to one another, and located one on each of opposite sides of said plane with their respective pivot axes substantially parallel thereto, and a further pivotal connection between respective ones of said pair of cutting members and said frame, said further pivot connection being located between the pivotal connections of the levers to said frame, each of said cutting members comprising a shear blade having a substantIally straight cutting edge which, in a shear jaw-closed position, are substantially parallel to one another in face-to-face abutting relation and, in a shear jaw-open position, converge inwardly toward one another in a direction toward the frame and thereby provide a widemouthed jaw in the latter position for receiving an article to be severed, said cutting members being movable in a direction toward and away from said selected plane for respectively severing an article grasped by the grapple and receiving an elongated article to be severed, and second power means for moving said cutting members relative to said selected plane.
 29. A felling head as defined in claim 26 including pivot means on said frame having a pivot axis substantially perpendicular to said selected plane for pivotally mounting the same directly to an extendible and retractable boom and located adjacent in said grapple and shear jaws.
 30. A felling head as defined in claim 26 including pivot means on said frame having a pivot axis substantially perpendicular to said selected plane for pivotally mounting the same directly to an extendible and retractable boom, said pivot means being located adjacent said grapple and shear jaws, and wherein said levers are located one on each of opposite sides of said selected plane and have their pivot axes substantially parallel thereto.
 31. A felling head as defined in claim 26 wherein said grapple jaw members are pivoted about respective ones of a pair of axes disposed one on each of opposite sides of said selected plane and wherein said levers are similarly located one on each of opposite sides of said plane.
 32. A shear comprising in combination: a. an elongated frame; b. two shear blades movable in a direction toward and away from one another respectively to sever and receive an article therebetween, said shear blades having at least a portion projecting outwardly away from the frame; c. two link means, means pivotally connecting said link means to said frame at respective first and second positions disposed in selected spaced relationship with respect to one another longitudinally along the frame, means connecting said link means to the respective shear blades at a position spaced from the pivotal connection of the same link to the frame; and d. further means providing interengagement of said cutting members and said frame at respective third and fourth positions spaced apart longitudinally along the frame and disposed between said first and second positions.
 33. A shear comprising in combination: a. an elongated frame; b. two shear blades movable in a direction toward and away from one another respectively to sever and receive an article therebetween, said shear blades having at least a portion projecting outwardly away from the frame; c. two link means, means pivotally connecting said link means to said frame at respective first and second positions disposed in selected spaced relationship with respect to one another longitudinally along the frame, means connecting said link means to the respective shear blades at a position spaced from the pivotal connection of the same link to the frame; d. further means providing interengagement of said cutting members and said frame at respective third and fourth positions disposed between said first and second positions, and e. power means interconnecting said link means for effecting movement of the same controllably to move the shear blades respectively toward and away from one another for severing and receiving an article therebetween.
 34. A shear as defined in claim 33 characterized in that each of said two link means includes a portion projecting from said frame in a direction opposite to that of the shear blades and that said power means comprises a hydraulic piston-cylinder assembly connected to the said projecting portion of said link means thereby locating the shear blades and hydraulic piston-cylinder assembly respectively on oppositE sides of said frame.
 35. A shear as defined in claim 33 characterized in that said link means comprises a pair of lever arms pivotally connected to said frame respectively adjacent opposed ends thereof.
 36. A shear as defined in claim 33 characterized in that each shear blade has a substantially straight, longitudinally extending cutting edge.
 37. A shear as defined in claim 36 characterized in that each of said shear blades consists of a substantially flat platelike member having a cutting edge and wherein said plate members are disposed in a common plane.
 38. A shear for severing trees or the like comprising in combination: a. a frame; b. two shear blades attached to the frame in spaced relation relative to one another and having cutting edges substantially in alignment longitudinally along a major portion of their length in a shear jaw-closed position; c. link means pivotally connected at spaced positions to the frame and respective shear blades connecting the respective shear blades to the frame; and d. cam means for guiding said shear blades during movement thereof relative to the frame.
 39. A shearing device composed of: a. a main transverse frame structure with opposite transversely spaced ends; b. a pair of levers supported one adjacent each of the respective opposite ends of the frame structure to swing about spaced-apart, substantially parallel axes; c. a pair of blades forwardly of the frame structure and having opposed inner cutting edges in face-to-face relation; d. pivot means supporting the respective blades on the respective levers; e. cam means on the frame structure, engageable with the respective blades, adapted to angularly adjust the blades on their respective pivot means in response to their being moved relative to one another and the frame by the respective levers; and f. hydraulic motor means for pivoting the levers about their respective pivotal connections to the frame to effect movement of the cutting members.
 40. A shearing device composed of: a. a main frame structure with opposite transversely spaced ends; b. a pair of levers supported one adjacent each of opposite ends of said frame structure to swing about respective ones of a pair of axes spaced from one another, each of the levers having a portion projecting from said frame structure. c. a pair of blades pivotally connected to respective ones of the levers and having cutting edges in face-to-face relation; d. guide means on the frame structure engageable with the respective blades adapted to angularly adjust the blades about their respective pivotal connections to the levers during movement thereof relative to the frame in response to their being shifted by the respective lever; and e. hydraulic motor means for moving the levers about their respective pivotal connections to the frame structure.
 41. The structure as set forth in claim 40 in which the guide means are cams engaging the respective blades.
 42. The structure as set forth in claim 41 in which the cams are so positioned and shaped that as the levers shift the blades outwardly in respect to one another, the blade cutting edges will diverge in respect to one another in a direction away from the frame.
 43. The structure as set forth in claim 42 in which the blades are coplanar and the cutting edges will be forced by the cams to substantial abutment upon the levers shifting them to their innermost positions.
 44. The structure as set forth in claim 40 in which the hydraulic motor means is an extendible and retractable hydraulic cylinder and ram device with the hydraulic cylinder being connected to one lever and the ram being connected to the other end.
 45. The structure as set forth in claim 40 in which the levers are three-point levers, the hydraulic motor means is an extendible and retractable ram and cylinder, the levers swing about points intermediate their ends on the respective ends of the structure, means are on the forward ends of the levers pivotally connecting the same to the respective cutting members, and the rear ends of the levers are connected to the ram and cylinder respectively.
 46. The structure as set forth in claim 40 in which each blade is one-half of a circular plate with each of the respective cutting edges being along the diameter.
 47. A shear comprising in combination: a. an elongated frame; b. two shear blades movable in a direction toward and away from one another respectively to sever and receive an article therebetween, said shear blade having at least a portion projecting outwardly away from the frame and movable relative thereto for receiving and severing said article; c. two link means, means pivotally connecting said link means to said frame at respective first and second positions disposed in selected spaced relationship with respect to one another longitudinally along the frame, means connecting said link means to the respective shear blades at a position spaced relative to the pivotal connections of the same linked to the frame; and d. further means pivotally connecting said cutting members to said frame at respective third and fourth positions spaced apart longitudinally along the frame and disposed between said first and second positions.
 48. A shear mechanism comprising a frame having a guide channel in a portion thereof, at least one cutting member having a portion thereof located in said channel, and mounted on said frame, means for effecting movement of the cutting member, relative to the frame in a direction toward and away from an abutment on said frame, said cutting member having a cutting edge angularly disposed with respect to the direction of movement thereof and means mounting said cutting member on said frame comprising a first lever arm pivotally connected at a pair of spaced positions respectively to said cutting member and said frame, and a second pivotal connection, between said cutting member and said frame, disposed in said channel in spaced relation with respect to the lever arm, said second pivotal connection being movable, with respect to the frame, along a given path and guide means restricting movement of the same to said given path.
 49. The improvement as defined in claim 48 wherein said given path is angularly disposed with respect to the direction of reciprocal movement of said cutting member, said angularly related path and first pivot being so related as to provide arcuate movement of the cutting edge of the cutting member during movement thereof.
 50. A shear mechanism as defined in claim 48 wherein said frame comprises a pair of flat, substantially parallel plates disposed in selected spaced relationship and wherein said cutting member includes a portion disposed between said plates, the latter providing a further guide for the cutting member during movement thereof.
 51. A shear mechanism comprising in combination: a frame: a pair of cutting members; and means mounting said cutting members on said frame comprising a pair of lever arms each pivotally connected to said frame and a selected portion of respective ones of said pair of cutting members, the pivotal connection of said lever arms to said frame being disposed in selected spaced relationship with respect to one another, and a further pivotal connection between respective ones of said pair of cutting members and said frame, said further pivotal connections and lever arm pivots being so arranged that the cutting members each move in an arcuate path in a direction toward and away from one another, said cutting members each having a substantially straight cutting edge which, in a shear jaw-closed position, are substantially parallel to one another in face-to-face relation and, in a shear jaw-open position, converge inwardly toward one another in a direction toward the frame and thereby provide a widemouthed jaw in the latter position for receiving an article to be severed.
 52. The improvement as defined in claim 51 including a Guide channel in said frame and wherein each of said cutting members has a portion thereof slidably mounted in said guide channel.
 53. A shear for severing trees as defined in claim 52 wherein said channel is located in one side of the frame and extends along a selected portion of the length thereof.
 54. A shear mechanism as defined in claim 53 wherein said frame comprises a pair of flat, substantially parallel plates disposed in selected spaced relationship and thereby providing said guide channel and wherein said cutting members each include a portion disposed between said plates, the latter providing a guide for the cutting members during movement thereof relative to said frame.
 55. A shear as defined in claim 51 wherein said further pivotal connections comprise an elongated slot in said frame and a portion, associated with respective ones of the cutting members, projecting into the slot.
 56. A shear as defined in claim 51 including power means for effecting movement of said shear blades.
 57. A shear as defined in claim 56 wherein said power means includes a hydraulic piston-cylinder assembly.
 58. A shear as defined in claim 57 wherein said hydraulic piston-cylinder assembly is connected to said lever arms.
 59. A shear as defined in claim 58 wherein said hydraulic piston-cylinder assembly interconnects the pair of lever arms.
 60. A shear as defined in claim 59 wherein each lever arm includes a portion projecting from said frame in a direction opposite to that of the shear blades.
 61. A shear as defined in claim 60 wherein the hydraulic piston-cylinder assembly is connected to the said projecting portion of said pair of lever arms thereby locating the shear blades and hydraulic cylinder respectively on opposite sides of the frame.
 62. A shear as defined in claim 51 wherein each of said lever arms comprises a pair of rigid members located respectively one on each of opposite sides of the frame and the correspondingly oriented opposite sides of the shear blade associated therewith.
 63. A shear as defined in claim 51 wherein each of said cutting members consists of a substantially flat platelike member having a cutting edge and wherein said plate members are disposed in a common plane.
 64. A shear as defined in claim 51, wherein said frame has a channel in one side thereof and each of said cutting members has a portion slidable in said channel with the cutting edge of one member facing the cutting edge of the other member, said lever arms being pivotally connected to the frame adjacent opposed ends of said channel and wherein said other pivotal connections comprise sliding pivots each including a cam and a cam follower respectively associated with one of said frame and cutting member and the other of said frame and cutting member.
 65. A shear as defined in claim 64 including power means connected to said pair of lever arms to pivot the same about their respective pivotal connections to the frame for moving the cutting members in a direction toward and away from one another.
 66. A shear for use in severing trees comprising in combination: a. a rigid frame having an elongated channel therein; b. a pair of cutting members each having a portion thereof slidable in said channel and further including a cutting edge; c. a first pair of pivot means connecting respective ones of said pair of cutting members to said frame at a first pair of positions disposed in selected spaced relation relative to one another; d. a second pair of pivot means connecting respective ones of said pair of cutting members to said frame, said second pivot means of one cutting member being disposed in spaced relationship with respect to said first pivot means associated with said cutting member and movable relative thereto along a selected path; e. means guiding said second pivots along their respective selected paths; and f. means for moving said cutting members, relative to the frame, in a direction toward and away from one anothEr, including a pair of lever arms pivotally connected to said frame and to respective ones of said cutting members and means to move said lever arms.
 67. A shear as defined in claim 66 wherein said means for moving said lever arms includes a hydraulic piston-cylinder assembly interconnecting said pair of lever arms.
 68. A shear mechanism comprising in combination: a. a frame; b. a pair of lever arms each pivotally connected to said frame in selected spaced relationship with respect to one another; c. a pair of cutting members pivotally connected to respective ones of the pair of lever arms at respective ones of a pair of first positions and to said frame at respective ones of a pair of second positions all disposed in spaced relationship with respect to one another, said pair of second positions being movable relative to said frame along a selected path; d. power means for moving said cutting members in a direction toward and away from one another respectively to sever and receive an article therebetween; and e. means guiding said cutting members along said selected path during movement thereof.
 69. A shear for severing trees comprising: a. a rigid frame having an elongated channel in one side thereof and extending along a selected portion of said side; b. a pair of cutting members each having a cutting edge and a portion slidable in said channel, the cutting edge of one member facing the cutting edge of the other member; c. a pair of lever arms pivotally connected to a selected portion of respective ones of said cutting members; d. first means pivotally connecting each of said lever arms to said frame, one arm being adjacent one end of said channel and the other arm adjacent an opposite end of said channel; e. second means pivotally connecting each of said cutting members to said frame, said second means being disposed in spaced relationship with respect to said first means and including a cam and a cam follower respectively associated with one or the other of said frame and respective ones of the cutting members; and f. means selectively effecting movement of said pair of lever arms about their respective pivotal connections to the frame for moving the cutting members in a direction toward and away from one another.
 70. A shear as defined in claim 69 wherein each of said cutting members consists of a substantially flat platelike member having a cutting edge and wherein said platelike members are disposed substantially in a common plane.
 71. A shear for severing trees as defined in claim 55 wherein each of said lever arms includes a first and second portion disposed respectively on opposite sides of the frame and a third and fourth portion disposed respectively on similarly oriented opposite sides of the cutting member associated therewith and wherein the first means pivotally connecting the lever arms to the frame comprises a pin projecting through apertures in the first and second portions of the lever arm and the frame and wherein the second means pivotally connecting the lever arms to respective ones of the cutting members comprises a pin projecting through apertures in the third and fourth portions of the lever arms and the cutting members associated therewith.
 72. A shear as defined in claim 71 wherein each of said lever arms comprises a pair of rigid members located respectively one on each of opposite sides of the frame and the corresponding opposite sides of the cutting member associated therewith.
 73. A shear as defined in claim 72 wherein the means for effecting movement of the lever arms comprises a hydraulic cylinder having the piston rod portion thereof pivotally connected to one of the lever arms and the cylinder portion thereof pivotally connected to the other of the lever arms.
 74. A shear as defined in claim 73 wherein the cutting members are located adjacent on one side of the frame and said hydraulic cylinder is located adjacent an opposite side thereof.
 75. A shear as defined in claim 69 wherein said cutting edge is substantially straight in outline shape.
 76. Apparatus for mounting on a vehicle to fell standing trees comprising, in combination, an extendable and retractable boom, means on said boom adjacent one end thereof for mounting the same on a mobile vehicle and a felling head pivotally mounted on the boom adjacent an opposite end thereof, said felling head comprising in combination: a. a grapple having: i. a frame, ii. a pair of jaw members at least one of which is pivotally mounted on said frame for movement toward and away from the other and together providing a grapple jaw which may be selectively opened and closed relative to a selected plane passing between said jaw members, and iii. first power means connected to said movable grapple jaw member selectively to open and close said grapple jaw; b. a shear rigidly secured to said frame in fixed spaced relation, relative to said grapple jaw along said plane, said shear including i. a pair of cutting members mounted on said frame for movement relative thereto, each of said cutting members comprising a shear blade having a cutting edge movable in a direction toward and away from said selected plane respectively severing an article grasped by the grapple and receiving an elongated article to be severed, and ii. second power means controllably moving said cutting members relative to one another and said frame in a direction toward and away from said selected plane; and pivot means on said frame, adjacent said grapple and shear jaws, for pivotally mounting said felling head directly on an extendible and retractable boom or the like.
 77. A shear for use in severing trees comprising in combination; a. a rigid frame having an elongated channel therein; b. a pair of cutting members each having a portion thereof slidable in said channel and further including a cutting edge; c. a first pair of pivot means connecting respective ones of said pair of cutting members to said frame at a first pair of positions disposed in selected spaced relation relative to one another, said first pair of pivot means comprising a pair of lever arms pivotally connected to the frame adjacent respective ones of the pair of cutting members and pivotally connected to respective ones of the latter for moving the cutting members in a direction toward and away from one another and means further connecting each of said cutting members to the frame comprising a slidable second pivot means, movable along a selected path angularly disposed with respect to the general direction of movement of the cutting members; d. a second pair of sliding pivot means connecting respective ones of said pair of cutting members to said frame, said second pivot means of one cutting member being disposed in spaced relationship with respect to said first pivot means associated with said cutting member and movable relative thereto along a selected path, angularly disposed with respect to the general direction of movement of the cutting members; e. means guiding said second pivots along their respective selected paths; and f. means for moving said cutting members, relative to the frame, in a direction toward and away from one another. 